Dear Mr. Singh,

there are many positive aspects which mainly lie in the fields of raw material supply and hydrogeology. Joint spacing and width are of control on the fluid movement in hard rocks and thus are of ore control on fault-bound mineral deposits. As far as, e.g., the quarrying of ornamental stones, decoration stones and aggregates is concerned it is the spacing of joints, their infill and width which decide whether a deposits is workable or better cast aside as a target. Jointing is also an essential factor if you are going to harvest water in crystalline or hard rocks, in general. Engineering geologists will look at joints with a crying and laughing eye. Slope stability will be reduced under certain circumstances, particularly when dip of slope and joints have the same direction. Sometimes it may ease tunneling, sometimes in may even prevent them from doing so.

Applied geology cannot be done without taking a closer look at these structures.

Best regards

H.G.Dill

Dear Mr. Singh,

there are many positive aspects which mainly lie in the fields of raw material supply and hydrogeology. Joint spacing and width are of control on the fluid movement in hard rocks and thus are of ore control on fault-bound mineral deposits. As far as, e.g., the quarrying of ornamental stones, decoration stones and aggregates is concerned it is the spacing of joints, their infill and width which decide whether a deposits is workable or better cast aside as a target. Jointing is also an essential factor if you are going to harvest water in crystalline or hard rocks, in general. Engineering geologists will look at joints with a crying and laughing eye. Slope stability will be reduced under certain circumstances, particularly when dip of slope and joints have the same direction. Sometimes it may ease tunneling, sometimes in may even prevent them from doing so.

Applied geology cannot be done without taking a closer look at these structures.

Best regards

H.G.Dill

Mr. Singh,

Sometimes I have that type of question on my mind. Even since my junior high school age I have a question like "What is the benefit of learning integral calculation? It will not be used in our daily life and no effect to our society". But later I got the answer. 

Agree with what Mr. Dill said, rock joints is very important in applied geology and rock mechanics field.

Well, I did not answer to your question, but I believe that every knowledge is beneficial depends on how we apply it.

All rocks have joints in them. These joints cause anisotropy in strength and stiffness of rocks. For example, direction and spacing of joints can make the pressure bulb in rock foundations to extend to a depth equal to 4 times the width of the foundation, which otherwise 1.5 to twice the width. If we design foundations without considering this, and if there are shear zones at deeper depths, the foundations fail, causing loss to the society. If we don't consider the mechanical behaviour of jointed rocks in slope stability, we will end up with rock slides, wedge failures etc., which is dangerous to people living in these areas and to structures in and around. Improper understanding of jointed rock behaviour has led to collapse of tunnels in many places, causing deaths and property losses. Jointed rocks also amplify the earthquake motions unlike rocks free of joints, thus damaging the infrastructure. 

The study of the jointed rocks is very important for: 

- slope stability in rock masses  

- water circulation inside the rocks (I suggest to read the book: "Water circulation in rocks" Springer edition)

- tunnels construction (I suggest to read the book: "Engineering Geology for underground works" Springer edition)

The study of the jointed rocks is very important for: 

- slope stability in rock masses  

- water circulation inside the rocks (I suggest to read the book: "Water circulation in rocks" Springer edition)

- tunnels construction (I suggest to read the book: "Engineering Geology for underground works" Springer edition)

Thanks everyone for valuable suggestion and valuable answer!! 

I see some classic answers here, especially Harald's response.  In underground mining, orientation of joints, their  spacing, and their properties have so much controlling factor over whether a mining method or mine design will be successful or not. Stability of slopes, exposes much of society to potential risk.  The science and art of stabilizing slopes affects society everyday.

Mechanical behavior of the joints has direct influence on the following;

- Intensity and pattern of groundwater flow and permeability condition in the rock mass

- Joint compressive strength (JCS), joint frictional properties and joint shear strength

- Global rock mass strength

All these issues are related to the overall stability of mines, tunnels, underground caverns and slope stability (both natural and cut slopes), which are directly related to the society. Therefore, study on mechanical behavior of the joints in the rock mass certainly helps to the society.   

All very good answers to your question. 

For my part, your question reminded me immediately of the catastrophic failure of the Malpasset dam, which occurred on 2 December 1959 at 21:30.  I was a young teenager at the time and I still remember that terrible event when the Malpasset Dam collapsed completely, creating a 50m high tidal wave which wiped out the little town of Fréjus and killed over 400 people.  From what I read about the forensic studies of the failure, it was the undetected presence of joints in the otherwise very sound gneiss rock, which led to that catastrophic failure.  The joints were unfortunately inclined in an unfavorable way and provided preferential slip surfaces for the downstream movement of the abutment, as pore pressures built up inside the joints.

Thus, the short answer to your question is indeed the knowledge of the mechanical behavior of rock joint can be of great importance to the welfare of society.

Mr Singh:

Suppose I asked the question "What is the benefit to Society in building with cracked concrete, split wood, shattered glass, halved bricks and so on?" The answer would be of course: "Stupid question. Why would anybody dream of engineering with failed building materials!". 

And now to answer your question: geological engineers, miners, tunnellers, petroleum and gas engineers, quarry folk, etc all have to work with the often severely failed material of rock masses. No- that is nowhere as nice as workign with lovely unbroken concrete, glass, wood etc..  But it is Reality. So Society, or at least the handmaidens of society (geopractitioners) had better understand the mechanical, geological, geohydrological, whateverologicals of Real Rock. 

If you are interested, I wrote a paper a few years of ago titled "Geopractioner approaches to working with antisocial melanges" , which addressed the Reality of having to work with melanges- some of the very worst of the failed/sheared/broken/cracked.shattered/etc rocks. Emauil me if you want a PDF - it is copyrighted and not freely available, although you can read the Abstract gratis (http://specialpapers.gsapubs.org/content/480/261.abstract)

Thank you very much to all !!! 

Edmund Medley! Super answer to a good question!